Patients receive rituximab IV on days 1, 8, 15, and 22. Patients then receive low-dose aldesleukin subcutaneously (SC) on days 29-39, 43-53, 57-67, and 71-81, and intermediate-dose aldesleukin SC on days 40-42, 54-56, 68-70, and 82-84. Cohorts of 3-6 patients receive escalating doses of intermediate-dose pulse aldesleukin until the maximum tolerated dose (MTD) is reached. The MTD is defined as the dose preceding that at which at least 2 of 6 patients experience dose-limiting toxicity.